This invention relates to a memory card and more particularly to a memory card connectable to a computer peripheral device through an electrical connector.
Generally, in order to obtain reliable electrical connections and to enable connection and disconnection to be repeatedly performed, a memory card is connected to a computer peripheral device by means of a two-piece connector. A twopiece connector comprises female contacts which are secured to the memory card and pin contacts which are secured to the peripheral device to which the memory card is to be connected. The force required to connect and disconnect a pin contact and a conventional female contact is approximately 80 grams per pin, so for a 60-pin two-piece connector, the total force required for connecting or disconnecting is 80 grams.times.60 pins=4.8 kg. With a force of this magnitude, connection and disconnection are difficult to perform, and accordingly there is a great interest in reducing the number of pins required for electrical connection of a memory card. By using the socalled I/O bus method, only 20 pins are required for a memory card having a capacity of up to 8 megabytes, so the connecting and disconnecting force for such a memory card is reduced to 80 grams.times. 20 pins=1.6 kg. However, this force is still too high to enable easy connection and disconnection, and there many cases in which the reading and writing of data into a memory card can not be performed due to incomplete connection using a conventional two-piece connector. Furthermore, this force is too high to enable use of an automatic loading mechanism such as is used for 3.5" floppy disks.
In order to solve the problem of connecting a memory card to a peripheral device, memory cards have been proposed which employ radio wave couplers, optical couplers, or magnetic couplers instead of conventional two-piece connectors. For example, Japan LSI Card Co. has manufactured a memory card employing a magnetic coupler. However, all of these memory cards have drawbacks with respect to cost, the area of the interface portion, data access speed, and power consumption. Accordingly, there is still a great need for a memory card connector which can be connected to a peripheral device as easily as a floppy disk can be loaded into a disk drive. In particular, there is a desire for a memory card which can be automatically connected to a peripheral device by an automatic loader, just as a 3.5" floppy disk can be automatically loaded into a disk drive.